The field of the present invention is generally that of support and adjusting structures for precision optical instruments and, more particularly, supports and adjusting structures for microscopes manufactured from low cost yet highly accurate extruded parts.
In the past, the exceedingly accurate tolerances demanded of optical instruments, such as microscopes, required precision machined parts which are quite expensive to manufacture and, thus, add substantially to the final cost of the instrument. In an attempt to control the cost, many individual parts of the microscope, such as the base, column and arm, were produced from for example, sand or die castings. The castings were then machined to final and quite precise working dimensions. Some of the machining procedures required were: drilling and tapping holes for mounting various parts; machining surface, such as bearing ways, to assure correct optical motion and machining of at least some exterior surfaces for esthetic purposes. Each additional machining increases the final cost of the product.
As an indication of the steps necessary to finish a typical microscope column, the following rather extensive machining procedures will be described. After the column casting has been received from the foundry it is necessary to drill and tap all mounting holes. As there are generally numerous holes to be drilled and tapped, the column casting must be continually mounted, removed and re-mounted in appropriate drilling fixtures. Further, all portions of the casting which require surfacing procedures must be similarly mounted, removed and re-mounted on the required piece of machinery.
It is readily apparent that the numerous and precise machining procedures required to produce one component part, such as the above-described microscope column, add significantly to the cost and complexity of the final product. Further, each additional procedure required in the manufacture of an instrument increases the likelihood of error being manufactured into the instrument. When precision optical instruments are involved, any such errors, no matter how slight, are unacceptable.
A further problem faced by the manufacturer and the ultimate user of precision optical instruments, such as microscopes, is the need to have readily available a wide and varied range of instruments to serve the immediate needs at hand. For example, in many instances a microscope of low power of magnification is sufficient to accomplish the examining task whereas in other instances a microscope having a fairly high power of magnification is required. Still other instances require a microscope having stereoscopic capability. Other variations may require that external or internal lighting be provided. Still other variations may call for substantial differences in the size and shape of the microscope base and column. Large objects may require a relatively long column and large base. Conversely, small objects may only require a short column and small base. Still other examination procedures may require a microscope providing a substantial amount of focus travel whereas others may require only very slight focus excursions.
At least some of the heretofore mentioned problems were addressed by R. W. Hodgson in U.S. Pat. No. 4,509,834 issued Apr. 9, 1984. Mr. Hodgson recognized and described the need for a microscope stand which offered the capability of initially attaching to the stand through an auxiliary supporting structure a desired set of microscope optics which could be, at a later time, optically aligned by a relatively unskilled worker. Although this apparatus does allow for the reduction of labor necessary to complete one step of the assembly procedure and the possibility of interchangeability of parts, it does not address or contemplate the problem of complexity of manufacturing and assembly. Accordingly, there would be a substantial increase in the final cost of the microscope.
U.S. Pat. No. 3,307,896 issued Mar. 7, 1967 to P.A. Hoogesteger sets forth a low power microscope which, for purposes of cost savings and mass production, is molded from plastic. While this microscope was inexpensive to manufacture it was only satisfactory for low power applications and offered no capability for precision adjustments nor any potential for adapting other optics or accessories.
A further low cost microscope which lends itself to mass production is disclosed in U.S. Pat. No. 3,328,109 issued June 27, 1967 to F. A. Seedhouse. In particular, Seedhouse discloses a stereomicroscope which, for purposes of economy and ease of construction, is manufactured from a minimum number of parts, at least some of which are plastic. However, there is no provision for interchangeability of parts such as, for instance, removing the stereo systems and replacing it with a mono system. Additionally, no accessories or options may be added to this microscope.
In U.S. Ser. No. 650,927 filed Sept. 14, 1984, M. Dobner, a co-inventor hereof, a mechanism is disclosed which removes play from the linear motion of a microscope slide assembly mounted to a vertical column. Although not specifically referred to as such in the specification of this application, the column was an extrusion.
Therefore, it will be readily appreciated that in the past a significant number of separate and distinct microscopes were required to be produced by a manufacturer, stocked by a dealer and possessed by an end user to satisfy the many and varied tasks being undertaken.
Accordingly, a very distinct yet unfulfilled need has existed for a microscope which is of high quality, yet is inexpensive to manufacture. A microscope of this type would further provide for simple interchangeabilty of parts allowing for many types of microscopes to be readily and easily constructed from stock parts. Furthermore, an unsatisfied need exists for a high quality, precision microscope which is manufactured from inexpensive extruded parts.